Th17细胞通过M2型巨噬细胞途径在结直肠癌中的调节机制研究

发布时间：2018-10-18 20:18

【摘要】：结直肠癌是世界范围内的高发癌症,其发病机理尚不明确。现有研究表明,白介素17和白介素22与肠炎和结直肠癌的发生发展密切相关。由于Th17细胞是分泌白介素17和白介素22的重要细胞类型,因此Th17细胞在结直肠癌的发生发展中可能产生重大作用。然而,对此类细胞的相关机理研究却少之又少.本课题探讨了Th17细胞在结直肠癌中的调节机制。研究共分为四个部分。1.探讨结直肠癌患者Th17细胞的数量改变。征集了诊断为结直肠癌且尚未治疗的17例患者和实验组年龄性别匹配的健康对照13例,并检测和其外周血的各项指标。实验结果：发现结直肠癌组分泌白介素17和白介素22的CD4+T细胞的表达水平显著升高,而大多数表达白介素22的CD4+T细胞也表达白介素17,表明结直肠癌患者体内Th17细胞比例上升。2.探讨结直肠癌患者Th17细胞的功能改变。通过ELISA等实验检测和对比了结直肠癌患者和健康对照组的PBMC中白介素17和白介素22的水平。实验结果：结直肠癌病人PBMCs分泌的白介素17和白介素22水平皆显著高于健康对照组,表明结直肠癌患者Th17细胞的细胞因子分泌功能增强.3.探讨单核细胞通过白介素6途径调节Th17细胞的机制。使用自体单核细胞或单克隆抗体白介素6诱导幼稚(CD45RA+CD45RO-)CD4+T细胞,并与只有单核细胞的对照组进行比较.细胞共计培养12天,分别检测细胞因子分泌情况.实验结果：白介素17和白介素22的产生需要自体单核细胞的辅助,减少单核细胞表达可显著降低白介素17和白介素22的分泌。结直肠癌患者的幼稚T细胞最初并不分泌白介素17和白介素22,但当长期与自体单核细胞共培养时则显著上调白介素17和白介素22的产生,而这种上调是通过白介素6途径完成。4.Th17对于CD163+M2巨噬细胞的反馈作用。从CD4+T细胞中分选出CCR4+CCR6+Th17细胞和非Th17细胞,并分别使用自体单核细胞进行共培养,检测巨噬细胞的表型。实验结果：与使用非‘Th17-CD4+T细胞相比,CCR4+CR6+Th17细胞培养单核细胞可导致更高水平的CD163+M2巨噬细胞比例以及白介素6的分泌增加,预示着结直肠癌病人中存在Th17和M2巨噬细胞之间的正反馈机制。结论：结直肠癌通过Th17和M2巨噬细胞的正向调节,致使Th17细胞分泌白介素17和白介素22上升,以达到促进肿瘤自身增殖发育的目的。此项研究解释了结直肠癌一个崭新的致病机理。
[Abstract]:Colorectal cancer is a worldwide high incidence of cancer, its pathogenesis is not clear. Current studies have shown that IL-17 and IL-22 are closely associated with the occurrence and development of colitis and colorectal cancer. As Th17 cells are important types of interleukin-17 and interleukin-22 secreting cells, Th17 cells may play an important role in the development of colorectal cancer. However, there are few studies on the mechanism of such cells. The aim of this study was to investigate the regulatory mechanism of Th17 cells in colorectal cancer. The research is divided into four parts. 1. To investigate the changes of Th17 cell count in patients with colorectal cancer. A total of 17 patients with colorectal cancer and 13 healthy controls matched by age and sex were recruited, and the indexes of peripheral blood and their peripheral blood were detected. The results showed that the expression of CD4 T cells secreting interleukin-17 and interleukin-22 was significantly increased in colorectal cancer group. The majority of CD4 T cells expressing interleukin 22 also expressed IL 17, suggesting that the proportion of Th17 cells in colorectal cancer patients increased by 2. 2. To investigate the functional changes of Th17 cells in patients with colorectal cancer. The levels of IL-17 and IL-22 in PBMC of rectal cancer patients and healthy controls were detected and compared by ELISA et al. The results showed that the levels of interleukin 17 and interleukin 22 secreted by PBMCs in colorectal cancer patients were significantly higher than those in healthy controls, indicating that the cytokine secretion function of Th17 cells in colorectal cancer patients was increased by 3. 3%. To explore the mechanism of monocyte regulation of Th17 cells through interleukin 6 pathway. Immature (CD45RA CD45RO-) CD4 T cells were induced by autologous monocytes or monoclonal antibody interleukin-6 (McAbs) and compared with those of monocytes only. Cells were cultured for 12 days and cytokine secretion was detected. Results: the production of interleukin-17 and interleukin-22 is assisted by autologous monocytes, and the secretion of interleukin-17 and interleukin-22 can be significantly reduced by reducing the expression of monocytes. Immature T cells in colorectal cancer patients initially did not secrete interleukin-17 and interleukin-22, but when co-cultured with autologous monocytes for a long time, the production of interleukin-17 and interleukin-22 was significantly up-regulated. This is done through a interleukin-6 pathway. The feedback of 4.Th17 on CD163 M 2 macrophages. CCR4 CCR6 Th17 cells and non-Th17 cells were isolated from CD4 T cells and co-cultured with autologous monocytes to detect the phenotype of macrophages. The results showed that monocytes cultured with CCR4 CR6 Th17 cells could increase the percentage of CD163 M2 macrophages and increase the secretion of interleukin 6 in comparison with non 'Th17-CD4 T cells. This indicates that there is a positive feedback mechanism between Th17 and M 2 macrophages in colorectal cancer patients. Conclusion: the positive regulation of Th17 and M2 macrophages leads to the increase of interleukin-17 and interleukin-22 secreted by Th17 cells in colorectal cancer, so as to promote the proliferation and development of the tumor itself. This study explains a new pathogenesis of rectal cancer.
【学位授予单位】：中国人民解放军医学院
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R735.34

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